My dad is a shop forman for a GM dealership and he has told me before about having to deal with lemon law.He told me if you take your vehicle to your dealership and its still under warranty to have the same exact problem fixed more than three times you would qualify for lemon law. But it has to be the exact same problem for example if your head gasket blew and you took it to ford to get it fixed and they told you it was fixed and as soon as you get your car back turns out the head gasket still leaks so you take it back.And this happens more than three times that car could quailfy as a lemon.In your case if the exact same thing that they fixed the first time your cel came on still has not been fixed you might have a case but if something else is causing the same cel code I dont think it would work.